What is the truth about Moussa Koussa?

The idea that a senior Libyan diplomat who would normaly have diplomatic immunity would fly to the UK and then announce his resignation thus waiving his diplomatic immunity is not credible. Is it not more likely the version of events given by the Libyan Government spokesmen is true and that Moussa Koussa has flown to the UK for medical treatment or he has been abducted from Tunisia. Its inconceivable that he would fly to the UK with no guarantees of immunity. Cameron and Hague seem to be pressing their version of a defection almost with desperation. One wonders which regime is really starting to unravel.